This invention relates to a telephoto lens camera, and more particularly to a camera of the type in which a long optical path length is obtained for the telephoto lens by utilizing a space at an upper part of a camera body.
At present, there is a tendency to make compact cameras even smaller and thinner than those which are currently available, which necessitates that a wide angle lens having a short focal distance be used. In such the wide angle lens, there is the shortcoming that a main object can only be photographed as a small part of the picture unless the camera is brought close enough thereto, since the angle of view is large. Because of the foregoing, when the situation prohibits the photographer from bringing the camera close enough to the object, for example, at an athletic event or a literary exhibition, it is impossible to take a satisfactory large size picture with a compact camera which has a wide angle lens with a 35 mm focal length. In order to overcome this problem, there is known a dual lens camera, as disclosed in Japanese Patent Early Disclosure No. 52(1977)-143013, which includes a telephoto lens having a long focal length and a wide angle lens having a short focal length, so that the user may select between a telephotograph and a wide angle photograph. This dual lens camera is constructed as such that a telephoto lens is displaced toward the side from a front part of an exposure station. The light from the image passes though the telephoto lens and is radiated onto a first mirror disposed behind the lens. The light is reflected toward the side of the camera body by the first mirror so that it reflects onto a second mirror disposed in a front part of the exposure station. The light is then reflected onto a film located in the exposure station. Also, a wide angle lens is disposed in a front part of the second mirror, so that when a wide angle photograph is taken, the second mirror is slid away from the front part of the film to guide the photographing light passing through the wide angle lens to the film. However, when a telephoto lens having a long focal length, for example, a telephoto lens of 135 mm, is used, since the back focus is comparatively long, it is necessary to have a long distance between the first and second mirrors in accordance with the long focal length thereof. As a result, it is necessary to make the lateral length of the camera body very long. If the mirrors are increased in number, for example, four mirrors for providing a crank-shaped photographing optical path on a same plane, it is possible to obtain a sufficiently long optical path length without having a long lateral length of the camera body. However, the thickness of the camera body becomes large. That is, a mere increase in the number of mirrors is not sufficient to effectively make the camera body small and thin.
Generally, when a telephoto lens having a focal length of 135 mm or so is used, a satisfactory telephotograph can be taken in many cases. However, in some cases such as in photographing wild birds, a long distance between the object and the camera is required. Moreover, if the object is inaccessible, it is necessary to use an ultra-telephoto lens having a focal length of, for example, 300 mm. (300 mm lens has approximately 8 times the telephoto effect as a lens having a focal length of 35 mm.) Moreover, when this ultra-telephoto lens is mounted on a camera body, the camera body must be large as in the case of the 135 mm telephoto lens. Furthermore, when a plurality of telephoto lens having different telephoto effects are used, such as a combination of a telephoto lens and an ultra telephoto lens, a selective use thereof can be conveniently made possible depending on the desired result.